1. Field of the Invention
The invention relates to suture anchors for securing sutures and other filamentary material to soft tissue. More particularly, the invention relates to suture anchors for securing sutures and similar filamentary material to soft tissue to reattach the soft tissue to bone. Still more particularly, the invention relates to suture anchors for knotlessly securing suture and filamentary material at a surgical site.
2. Description of the Prior Art
In situations where ligaments or other soft tissue are being secured to bone, a suture anchor is commonly employed. The anchor is generally inserted into a preformed hole in the bone and a suture or similar filamentary material extends from the anchor and is attached to the soft tissue to be secured to the bone. As used herein, the term “suture” includes monofilament or multi-filament suture as well as any other metallic or non-metallic filamentary or wire-like material suitable for performing the function of a suture including both absorbable and non-absorbable materials.
Whether such surgical procedures are done open or closed, in most instances, the suture must be tied to the soft tissue so that a knot must be formed. When such procedures are done arthroscopically or endoscopically (i.e. closed), creation of a knot is somewhat difficult. As a result, knotless suture anchors have been recently developed to avoid the knot tying step.
One example of a knotless suture anchor is shown in U.S. Pat. No. 6,692,516 (West Jr. et al.) assigned to the assignee hereof and incorporated by reference herein. This patent discloses an expandable metallic knotless suture anchor, the design of which is difficult to implement with the use of non-metallic material. As used herein, the term “expandable” means the diameter of the device increases when it is deployed/anchored in the bone.
U.S. Published patent application 2005/0055052 (Lombardo et al.) discloses a knotless suture anchor which may be made of bioabsorbable material. This application is assigned to the assignee hereof and incorporated by reference herein. While the design disclosed in this reference is compatible with bioabsorbable material, the design is a press-fit design and is limited in the types of surgical procedures for which it is suitable. As used herein the term “press-fit” means the diameter of the device is substantially the same before and after deployment/anchoring in the bone.
In developing a knotless suture anchor for use in rotator cuff repairs, as well as other surgical procedures, it is preferable to assure that the anchor is provided with means to secure it to cancellous bone and means to limit any tendency to migrate above the level of the humeral head or other bone at the anchor site. An expandable design is preferable.
It is accordingly an object of this invention to produce a knotless suture anchor suitable for repairing a rotator cuff and re-attaching it to the humeral head.
It is another object of this invention to produce a non-metallic suture anchor suitable for knotlessly securing suture to attach a first body tissue to a second body tissue.